This multidisciplinary program is aimed at a detailed investigation of immunopathologic mechanisms especially as they pertain to defective leukocyte function in humans. Accordingly, patients with cancer, recurrent bacterial infections, and those with evidence of anergy will be investigated for leukotactic and phagocytic function. Serum inhibitors will be characterized. Enzymes of the human neutrophil that are involved in the normal chemotactic response will be identified. Where appropriate, cells from humans with a chemotactic defect will be analyzed for enzyme content. Attention will be paid to the cells from mice and humans with the Chediak-Higashi syndrome; microtubular function of leukocytes and the in vitro pharmacological modulation will be determined. Another part of these studies involves cellular immune mechanisms. Both the basic aspects of lymphokine biology will be assessed as well as lymphocytes from patients with cellular immune dysfunction. Finally, autoimmune aspects of systemic lupus erythematosus will be studied with a particular emphasis on the possible role of anti-DNA antibodies. BIBLIOGRAPHIC REFERENCES: Maderazo, E.G., Ward, P.A. and Quintiliani, R.: Defective regulation of chemotaxis in cirrhosis. J. Lab. Clin. Med. 85:621, 1975. Maderazo, E.G., Ward, P.A., Woronick, C.L., Kubik, J. and DeGraff, A.C.: Leukotactic dysfunction in sarcoidosis. Ann. Intern. Med. 84:414, 1976.